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So its been a while since my last blog as the last year or so has been manic in my $dayjob due to a number of projects and I have finally managed to take a breath and start to think of some content I can give back to the community. The following post comes with a big thanks to James for pointing me towards this great trick and educating me on some linux/unix commands!

Junos devices have the ability to examine packets destined for the routing engine in a number of ways.

Offline Wireshark

Transfer the file off the device via SCP and the trace can then be examined in a local install of wireshark. This is the best way to quickly examine captured packets but makes live debugging tricky

Live Wireshark

Due to Junos being built on Unix and using tcpdump for its underlying packet capture it is possible to redirect the tcpdump output from STDOUT via an SSH connection to a remote system where wireshark is installed for live packet capture. This remote system must be accessible from the device where packets are captured and not behind NAT unless there is a port forward in place. If the remote system is not a local laptop then X-Forwarding can be used to trigger a session that is forwarded to the local laptop.

On the remote system where wireshark is installed open an SSH connection with X-Forwarding enabled, show the current DISPLAY env and leave the session open.

So LinkedIn told me it was my 3 year workiversary the other day. 3 whole years since starting with Fluency Communications and building out their National Next Gen Network.

When I first joined the company, the network was ran on 3 Vyatta boxes and a few 100M circuits. From there we started the upgrade process to Juniper MX5 routers and some 1G links.

What made the MX platform stand out for us was the following:-

Stability of Junos OS

Rich feature set

Built in scripting tools (Netconf/SLAX)

Scalability

We required to have a box that would scale not only in performance but features. The MX5 can be easily unlocked from a 20G line rate box up to an MX10 giving 40G line rate performance with a simple license install (and further if you want). For us, EVPN is looking like a no brainer upgrade from VPLS with its control plane learning and mac learning/filtering with the use of policies. Sometimes it seems the possibilities are endless!

We have now outgrown the MX5/10 as our core router and we are now in receipt of some shiny MX480 routers (see below picture). We have also taken the decision to go single vendor, which up until the last year or so I always had an inherent distrust of but seeing the flexibility of the MX platform has removed that mental stumbling block and we are now using the MX104 at our access edge for customer connections rather than our previous vendor.

This allows us to look at things like Junos Space,Network Director and Connectivity Services Director to allow us to build service templates that will allow us to provision complex customer solutions and the click of a button rather than jumping onto several boxes and sitting at the cli for 20-30mins. This frees up my time to start looking at the next core network upgrade!

Have a great Christmas and a fantastic New Year!

P.S. Here’s a pic of our little MX evolution. From bottom to top – MX5, MX10, MX104 and an MX480!

Over the last few years I have made the transition at the company I work for, from Support Engineer to Network Engineer. In between this I became a Managed Services Engineer dealing with the configuration, installation and maintenance of Cisco 1800 series routers. During this time I decided I would use the knowledge gained in my day job to go on the certification trail. 4 months later I gained my CCNA accreditation and a thirst to obtain more understanding in networking in general.

So I was tasked to provide a failover mechanism for a customer with Juniper equipment without using OSPF.

With the L2 providers we use there is always a link from the CPE to the provider equipment and then it breaks out to their backbone. Now, this means that there could be a break in the provider network and the customer CPE would still see the link as up. We would then be blindly forwarding traffic into a black hole. Continue reading →

It is amazing how sleepy you feel when sitting in a relatively dark auditorium after a buffet lunch.

I sat through a presentation on Junosphere which looked fantastic and just what the community has been crying out for so we no longer require to use olive’s that we cannot get support for. Continue reading →